Products such as foods and pharmaceuticals are susceptible to water (moisture) and may absorb water. If this occurs, foods may spoil or mold may grow thereon, while pharmaceuticals may undergo deterioration of the medicinal properties thereof or a decrease in performance. Consequently, packets having a desiccant such as silica gel sealed therein have conventionally been placed in food and pharmaceutical packaging. However, the work of placing packets of desiccants in packaging has frequently been performed manually making it labor-intensive. In addition, there was also the risk of such packets being swallowed or consumed accidentally. Consequently, there has been a desire to provide packaging per se with a function that allows it to absorb water and the like.
Moreover, since some foods and pharmaceuticals are susceptible to oxidative degradation while some products have a characteristic odor, there has also been a desire to absorb oxygen and odors present in packaging.
In response to such desires, Patent Document 1 discloses a desiccant-incorporating resin composition and a desiccant-incorporating resin formed product that uses that composition. Here, after having mixed a molecular sieve which is a desiccant with a base resin having a melt flow index (MFR) of 10 or more followed by forming into a pelletized resin, an ethylene-acrylic acid ester-maleic anhydride copolymer is mixed as an additive with the pelletized resin to fabricate a desiccant-incorporating resin composition. Moreover, this desiccant-incorporating resin composition is subjected to extrusion formation or injection formation to fabricate a desiccant-incorporating resin formed product.
Molecular sieves are porous particulate substances that are used to separate substances according to differences in molecular size, have a structure that has uniform pores, and are typically synthetic zeolite that has the action of a type of sieve that absorbs small molecules that enter voids within the pores. Since the substance absorbed differs according to the size of the pores, water, water vapor or organic gas and the like can be absorbed. Since the containing of a molecular sieve makes it possible to provide packaging per se with the ability to absorb water, water vapor or organic gas (odors), spoilage or deterioration and the like of the contents thereof is thought to be able to be prevented without having to separately place a packet containing a desiccant in the packaging.